Zone 2 Endurance Turbo Ride: Build Your Aerobic Base

Session Overview

This 60-minute Zone 2 turbo session is the cornerstone of triathlon base training. By keeping your effort in the aerobic zone — where you can comfortably hold a conversation — you build the fat-burning efficiency and cardiovascular foundation that powers all your harder efforts later in the season.

What You’ll Need

• Turbo trainer or smart trainer
• Heart rate monitor — essential for keeping you in the correct zone
• Cycling computer or phone with training app
• Fan — overheating pushes HR above Zone 2
• 2 x water bottles

Warm-Up (10 minutes)

Start with 10 minutes at a very easy effort, letting your heart rate settle and your muscles loosen. Aim for Zone 1 (below 65% of max HR). Gradually bring your cadence up to 85–90rpm.

Main Set

40 minutes at Zone 2 intensity: 65–75% of your maximum heart rate, or approximately 55–65% of FTP if you have power. Your breathing should be elevated but controlled — you should be able to speak in short sentences. Maintain a steady cadence of 80–90rpm throughout.

• Target heart rate: 65–75% max HR (Zone 2)
• RPE: 4–5 out of 10 — genuinely easy, never uncomfortable
• Cadence: 80–90rpm, smooth and circular pedal stroke
• If HR drifts above Zone 2, reduce resistance — resist the temptation to push harder

Cool-Down (10 minutes)

Ease off for 10 minutes, dropping to Zone 1 and then a very easy spin. Stretch your hip flexors and lower back after dismounting — indoor training shortens the hip flexors more than outdoor riding.

Coaching Notes

• Zone 2 develops mitochondrial density and fat oxidation — the bedrock of endurance fitness
• Most common mistake: riding too hard. If in doubt, go easier
• Cardiac drift: HR naturally creeps up during long rides even at constant power — this is normal
• Ideal frequency: aim for 2–3 Zone 2 sessions per week during base building phase
• Scale up: progress to 75 or 90 minutes as the season advances